The present invention relates to the field of fire protection in buildings and, in particular, high-security buildings, and relates to a fire door assembly having one or two swiveling door leaves.
It is known that in high-security buildings, particularly those using a nuclear source, must meet many requirements in response to accidental or intentional assaults such as fires.
To combat these assaults, it is known to implement fire door assemblies having one or two swiveling door leaves, thereby making it possible to prevent the disaster (fire or smoke) from spreading into the buildings concerned by compartmentation and confinement of the areas on fire, while dividing these buildings into various protected areas.
A current fire door assembly must thus meet several constraints and requirements such as fire stability (flame resistance), gas and smoke-proofness and heat insulation over a specific time period.
Such fire door assemblies are intended to be mounted in an opening or bay, which is specifically rectangular or square, and which is made in a masonry structure usually extending substantially vertically, such as a wall. They generally consist of a fixed frame extending substantially vertically when mounted in said bay, and comprising substantially two vertical uprights joined by a horizontal upper cross-member and by one or two door leaves each swiveling about a vertical axis by means of at least two loose-joint hinges, said fixed frame being capable of being at least partially inserted into a recess made in the opening of said bay and open outwardly, i.e., towards the area of travel of the or each door leaf.
Hereinbelow (or hereinafter), the visible and exposed surface in the state wherein said door assembly is mounted in the corresponding bay and in the closed position of the or each door leaf, relative to an observer situated in the area of travel of the or each door leaf, will be described as the front surface of the door assembly. The non-visible or unexposed surface thereof, in mounted state and closed position of each door leaf, relative to said observer, will be described as the rear surface of the door assembly.
Furthermore, in this type of fire door assembly, provisions are generally made for the door leaf to be provided with a rigid metal peripheral frame, in order to reinforce its structure and rigidity thereof, and for fire barriers and/or intumescent seals to be placed between the or each door leaf and the fixed frame or between the latter and the masonry structure, in order to make it possible to slow down rises in temperature and the spread of toxic fumes.
In addition, fire door assemblies must comply with regulations in force concerning fire safety and, in this regard, must be subject to fire tests during which temperature sensors or thermocouples are placed at various control points or reference areas on the door assembly, namely on the or each door leaf and/or on the fixed frame, specifically in proximity to the peripheral area of same and on the unexposed side generally corresponding to the rear surface of said door assembly.
Such being the case, measurements taken by said sensors on existing door assemblies, in particular according to the latest classifications of current standards, reveal significant increases in temperature, which do not enable effective fire resistance to be obtained for same. This is primarily due to the structure of the fixed frames and, where appropriate, those of the peripheral frames of the current door leaves, which are made of tubular metal profile members comprising many surfaces apparent or not, exposed to fire and increases in temperature, which do not enable the thermal bridge between the various constituent elements of the door assembly to be effectively broken and, in particular, between said exposed surfaces and the regulatory measurement areas where the sensors are placed.